Easily dispersible pigments with fast colour intensity development

ABSTRACT

The invention relates to a method for the pigmentation of a non-aqueous, organic coating material containing a solvent. The invention is characterised in that a coated, finely dispersed organic pigment with (meth)acrylate copolymers containing amino groups is incorporated into an organic coating material containing a solvent, said pigment having a discharge of energy which is reduced by at least 20% compared to the corresponding non-coated pigment.

The surface modification of pigments using pigment derivatives andcompounds of low molecular mass is known, though in many cases theperformance with regard to ready dispersibility in the applicationmedium is inadequate.

Easy-to-disperse pigments or solid pigment preparations, alsoencountered in the technical literature under the designation of stir-inpigments, have already been the subject of numerous investigations. Inorder to ensure high, universal compatibility with the applicationmedium, it is necessary to select a high pigment concentration, which innumerous liquid pigment preparations is non-achievable.

EP-0 902 061 describes how by coating the surface with vinylpyrrolidonepolymer and/or copolymer a modified pigment powder is obtained whichwithout using a ball mill can be incorporated into an aqueous printingand grinding system.

EP-0 702 062 describes the modification of pigments with rosin, anaqueous suspension of pigment, alkali metal salt of a rosin acid, and afiller being ground in a horizontal ball mill. Adding a metal saltallows the stir-in pigment to be isolated.

WO 02/26892 discloses a process for preparing polymer-enrobed pigmentparticles wherein, with finely divided pigment particles present, asolution of a polymer in a first solvent is mixed with a second solventwhich has very little or no solvency for the polymer but is misciblewith the first solvent. Prior to mixing, the pigment particles may be infinely divided form in the solution of the polymer in the first solventand/or in finely divided form in the second solvent. The turbulentmixing of the two solvents causes the polymer's solubility limit to beexceeded and the polymer to be precipitated on the pigment surface. Itthus encapsulates the pigment particles. This process has thedisadvantage, however, that the product is a low-pigment-contentdispersion and the dispersion, moreover, contains environmentallyobjectionable organic solvents. Isolating the polymer-enrobed pigmentparticles here also necessitates expensive distillation of both solventsor energy-intensive spray drying.

The object, then, was to provide a technically simple andenvironmentally unobjectionable method of pigmenting solventborneorganic coating materials, such as paints and inks, wherein organicpigments can be incorporated in said organic paints and inks withminimal shearing forces and maximum, fast color intensity development.

Surprisingly it has been found that pigments surface-coated with certaincopolymers exhibit very high suitability as stir-in pigments for organiccoating materials, with an increase in color intensity development atthe same time.

The invention provides a method of pigmenting a solventborne, nonaqueousorganic coating material which comprises incorporating a finely dividedorganic pigment coated with amino-containing (meth)acrylate copolymersinto a solventborne organic coating material with an energy inputreduced by at least 20% as compared with the corresponding uncoatedpigment.

The stir-in pigments produced in accordance with the invention developtheir high color intensity by being stirred simply and with shortduration into the solventborne organic coating material: for example, by5-minute to 3-hour stirring, preferably 15- to 45-minute stirring, in adissolver with a toothed disk, so that there is no need for moreextensive, expensive dispersing steps in the stated application medium.

The production of the coated pigments, too, is characterized by a simpleprocedure. Costly and inconvenient isolation by means of expensivedistillation steps of the entire liquid phase or by spray drying isunnecessary. In addition, the method of the invention is applicable inprinciple to all organic pigments, since there is no sharp change in pH,as described in EP-0 702 062 for producing stir-in pigments by means ofsoluble alkali metal salts of various resins.

In one preferred embodiment the finely divided, coated organic pigmentis obtained by mixing an aqueous, finished presscake of the organicpigment with water and carrying out deagglomeration in a static mixer inthe presence of the amino-containing (meth)acrylate copolymer, thensubjecting the deagglomerated mixture to steam distillation, isolatingthe solid by filtration, and drying it. Said aqueous presscake of theorganic pigment is composed of pigment which has been finely divided,ground for example, and, if desired, finished. The techniques of finedivision and finishing that are the most favorable in each case aredependent on the identity of the pigment and are known to the skilledworker. The aqueous presscake is diluted with water to a solids contentof preferably 5% to 30% by weight.

Added to the aqueous suspension obtained in this way is a solution ofthe amino-containing (meth)acrylate copolymer or of a mixture of suchcopolymers. The amount of this solution is calculated such thatultimately the amino-containing (meth)acrylate copolymer is applied inan amount of 5% to 50% by weight, especially 10% to 40% by weight, tothe pigment, based on the total weight of the coated pigment. Suitablesolvents for the amino-containing (meth)acrylate copolymers include, inparticular, organic solvents which are immiscible or poorly misciblewith water, such as butyl acetate, 1-butanol, 2-butanol, and isobutanol,or else solvent mixtures of these solvents with one another and alsowith methoxypropyl acetate.

In one particularly preferred embodiment the suspension, during or afterthe addition of the amino-containing (meth)acrylate copolymer, issubjected to deagglomeration in a static mixer, in which case it isparticularly advantageous to pump the suspension repeatedly incirculation through the static mixer until a particle size d₅₀ of 0.05to 40 μm, especially 0.1 to 10 μm, is attained.

Static mixers are comminution machines such as ball mills and bead millswith glass, porcelain or steel balls/beads. Also possible, furthermore,are dissolvers and comminuting machines of rotor/stator design. Oneparticularly preferred embodiment uses a rotor/stator machine with highperipheral speeds. Common to all of the constructions is the ability touse a high energy component effectively for comminuting the pigmentparticles.

The stir-in pigment is isolated by removing the organic solvent to givean aqueous suspension. Steam distillation is found particularlyadvantageous. The surface-coated, easily dispersible stir-in pigment isobtained by filtration and final drying. If the stir-in pigment isobtained in the form of coarse grains, it is advantageously subjected todry grinding in addition. The coated pigments produced in accordancewith the invention generally have a specific surface area (BET) ofbetween 5 and 30 m²/g, preferably 7 and 20 m²/g, especially 8 and 15m²/g.

The organic pigment may be a pigment from the group of the azo pigments,such as monoazo, disazo, Naphtol, benzimidazolone, and metal complexpigments, or of the polycyclic pigments, such as isoindolinone,isoindoline, anthanthrone, thioindigo, thiazineindigo, triarylcarbonium,quinophthalone, anthraquinone, dioxazine, phthalocyanine, quinacridone,quinacridonequinone, indanthrone, perylene, perinone, pyranthrone,diketopyrrolopyrrole, isoviolanthrone and azomethine pigments.

Preferred organic pigments for the purposes of the present inventionare, for example, C.I. Pigment Yellow 1 (C.I. No. 11 680), C.I. PigmentYellow 3 (C.I. No. 11 710), C.I. Pigment Yellow 12 (C.I. No. 21 090),C.I. Pigment Yellow 13 (C.I. No. 21 100), C.I. Pigment Yellow 14 (C.I.No. 21 095), C.I. Pigment Yellow 17 (C.I. No. 21 105), C.I. Pigment Red123 (C.I. No. 71 145), C.I. Pigment Red 149 (C.I. No. 71 137), C.I.Pigment Red 178 (C.I. No. 71 155), C.I. Pigment Red 179 (C.I. No. 71130), C.I. Pigment Red 190 (C.I. 71 140), C.I. Pigment Red 224 (C.I. No.71 127), C.I. Pigment Violet 29 (C.I. No. 71 129), C.I. Pigment Orange43 (C.I. No. 71 105), C.I. Pigment Red 194 (C.I. No. 71 100), C.I.Pigment Violet 19 (C.I. No. 73 900), C.I. Pigment Red 122 (C.I. No. 73915), C.I. Pigment Red 192, C.I. Pigment Red 202 (C.I. No. 73 907), C.I.Pigment Red 207, C.I. Pigment Red 209 (C.I. No. 73 905), C.I. PigmentRed 206 (C.I. No. 73 900/73 920), C.I. Pigment Orange 48 (C.I. No. 73900/73 920), C.I. Pigment Orange 49 (C.I. No. 73 900/73 920), C.I.Pigment Orange 42, C.I. Pigment Yellow 147, C.I. Pigment Red 168 (C.I.No. 59 300), C.I. Pigment Yellow 120 (C.I. No. 11 783), C.I. PigmentYellow 151 (C.I. No. 13 980), C.I. Pigment Brown 25 (C.I. No. 12 510),C.I. Pigment Violet 32 (C.I. No. 12 517), C.I. Pigment Orange 64; C.I.Pigment Brown 23 (C.I. No. 20 060), C.I. Pigment Red 166 (C.I. No. 20730), C.I. Pigment Red 170 (C.I. No. 12 475), C.I. Pigment Orange 38(C.I. No. 12 367), C.I. Pigment Red 188 (C.I. No. 12 467), C.I. PigmentRed 187 (C.I. No. 12 486), C.I. Pigment Orange 34 (C.I. No. 21 115),C.I. Pigment Orange 13 (C.I. No. 21 110), C.I. Pigment Red 9 (C.I. No.12 460), C.I. Pigment Red 2 (C.I. No. 12 310), C.I. Pigment Red 112(C.I. No. 12 370), C.I. Pigment Red 7 (C.I. No. 12 420), C.I. PigmentRed 210 (C.I. No. 12 477), C.I. Pigment Red 12 (C.I. No. 12 385), C.I.Pigment Blue 60 (C.I. No. 69 800), C.I. Pigment Green 7 (C.I. No. 74260), C.I. Pigment Green 36 (C.I. No. 74 265); C.I. Pigment Blue 15:1,15:2, 15:3, 15:4, 15:6 and 15 (C.I. No. 74 160); C.I. Pigment Blue 56(C.I. No. 42 800), C.I. Pigment Blue 61 (C.I. No. 42 765:1), C.I.Pigment Violet 23 (C.I. No. 51 319), C.I. Pigment Violet 37 (C.I. No. 51345), C.I. Pigment Red 177 (C.I. No. 65 300), C.I. Pigment Red 254 (C.I.No. 56 110), C.I. Pigment Red 255 (C.I. No. 56 1050), C.I. Pigment Red264, C.I. Pigment Red 270, C.I. Pigment Red 272 (C.I. No. 56 1150), C.I.Pigment Red 71, C.I. Pigment Orange 73, C.I. Pigment Red 88 (C.I. No. 73312), C.I. Pigment Yellow 175 (C.I. No. 11 784), C.I. Pigment Yellow 154(C.I. No. 11 781), C.I. Pigment Yellow 83 (C.I. No. 21 108), C.I.Pigment Yellow 180 (C.I. No. 21 290), C.I. Pigment Yellow 181 (C.I. No.11 777), C.I. Pigment Yellow 74 (C.I. No. 11 741), C.I. Pigment Yellow213, C.I. Pigment Orange 36 (C.I. No. 11 780), C.I. Pigment Orange 62(C.I. No. 11 775), C.I. Pigment Orange 72, C.I. Pigment Red 48:2/3/4(C.I. No. 15 865:2/3/4), C.I. Pigment Red 53:1 (C.I. No. 15 585:1), C.I.Pigment Red 208 (C.I. No. 12 514), C.I. Pigment Red 185 (C.I. No. 12516), C.I. Pigment Red 247 (C.I. No. 15 915), and C.I. Pigment Red 146(C.I. No. 12 485).

It is also possible to use more than one organic pigment or mixedcrystals (solid solutions) of organic pigments.

Particularly preferred pigments are C. I. Pigment Violet 23 (C. I. No.51319) and C.I. Pigment Orange 36 (C.I. No. 11780).

The amino-containing (meth)acrylate copolymers are modified acrylatecopolymers and methacrylate copolymers having an amine number ofpreferably 20 to 70 mg KOH/g, more preferably 25 to 55 mg KOH/g. Themolar mass of suitable, modified acrylate copolymers and methacrylatecopolymers is preferably between 2000 and 100 000 g/mol. Especiallysuitable copolymers have molar masses of between 5000 and 30 000 g/mol.The amino groups may also have been quaternized and may be present, forexample, in ammonium salt form. The modified acrylate copolymers andmethacrylate copolymers can be block copolymers, graft copolymers orrandom copolymers. Also possible is the use of specific macromonomers.The copolymer may contain monomer units from the group of acrylic acidand methacrylic acid, such as, for example, methyl (meth)acrylate,ethyl(meth)acrylate, n-propyl(meth)acrylate, n-butyl(meth)acrylate,isopropyl(meth)acrylate, isobutyl(meth)acrylate, amyl (meth)acrylate,isoamyl(meth)acrylate, hexyl(meth)acrylate,2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,N,N-diethylaminoethyl(meth)acrylate,N,N-dimethylaminoethyl(meth)acrylate,N,N-dipropylaminoethyl(meth)acrylate,N,N-dibutylaminoethyl(meth)acrylate,N,N-dihexylaminoethyl(meth)acrylate,N,N-diethylaminobutyl(meth)acrylate,N,N-dimethylaminobutyl(meth)acrylate,N,N-dipropylaminobutyl(meth)acrylate,N,N-dibutylaminobutyl(meth)acrylate,N,N-dihexylaminobutyl(meth)acrylate,N,N-diethylaminopropyl(meth)acrylate,N,N-dimethylaminopropyl(meth)acrylate,N,N-dipropylaminopropyl(meth)acrylate,N,N-dibutylaminopropyl(meth)acrylate,N,N-dihexylaminopropyl(meth)acrylate,N,N-diethylaminohexyl(meth)acrylate,N,N-dimethylaminohexyl(meth)acrylate,N,N-dipropylaminohexyl(meth)acrylate,N,N-dibutylaminohexyl(meth)acrylate,N,N-dihexylaminohexyl(meth)acrylate, benzyl(meth)acrylate,allyl(meth)acrylate, 2-n-butoxyethyl(meth)acrylate, 2-sec-butyl(meth)acrylate, tert-butyl(meth)acrylate, 2-ethylbutyl(meth)acrylate,cyclohexyl(meth)acrylate, 2-ethoxyethyl(meth)acrylate, 3-methoxybutyl(meth)acrylate, 2-methoxybutyl(meth)acrylate, n-octyl(meth)acrylate,2-ethylhexyl (meth)acrylate, 2-phenylethyl(meth)acrylate,phenoxyethyl(meth)acrylate, and phenyl(meth)acrylate.

Further possible monomer units are as follows: styrene, α-methylstyrene,vinyltoluene, acrylic acid, methacrylic acid, 9-vinylanthracene,9-vinylcarbazole, vinylcyclohexane,

1-vinylimidazole, 2-vinylpyridine, 1-vinyl-1,2,4-triazole, andacrylnitrile.

The copolymer possesses no hydrophilic character or only slighthydrophilic character.

The application medium, i.e., the organic coating material to bepigmented, may be a solventborne baking varnish, a solventbornetwo-component varnish, or a printing ink or ink-jet ink. Solventborne inthis context means that the customary solvents employed in the coatingsindustry, with the exception of water, are suitable.

Examples of suitable varnishes are alkyd-melamine resin varnishes,acrylic-melamine resin varnishes, polyester varnishes, and high-solidsacrylic resin varnishes.

Particularly suitable application systems for the surface-modified,easily dispersible pigments are alkyd-melamine resin varnishes based ona medium-oil alkyd resin and a butanol-etherified melamine resin. Theratio of alkyd resin to melamine resin in the corresponding varnish isadvantageously between 70:30 and 80:20. Likewise suitable aretwo-component varnishes based on an isocyanate-crosslinkable acrylicresin.

Solvent-based ink-jet inks can contain 0.5 to 15% by weight of thestir-in pigment of the invention, 85 to 99.5% by weight of organicsolvent and/or hydrotropic compounds.

The solvents and/or humectants present in recording liquids may bemonohydric or polyhydric alcohols, their ethers and esters, e.g.,methanol, ethanol, propanol, isopropanol, butanol, and isobutanol;dihydric or trihydric alcohols, particularly of 2 to 6 carbon atoms,e.g., ethylene glycol, propylene glycol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol,glycerol, diethylene glycol, dipropylene glycol, triethylene glycol,polyethylene glycol, tripropylene glycol, and polypropylene glycol;lower alkyl ethers of polyhydric alcohols, such as ethylene glycolmonomethyl, monoethyl or monobutyl ether, and triethylene glycolmonomethyl or monoethyl ether; ketones and ketone alcohols, such asacetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone,methyl pentyl ketone, cyclopentanone, cyclohexanone, and diacetonealcohol; amides, such as dimethylformamide, dimethylacetamide, and

N-methylpyrrolidone; and also urea, tetramethylurea, thiodiglycol, andε-caprolactam.

Examples 1 to 3 describe the preparation of the surface-coated, easilydispersible pigments and Examples I-V describe incorporation into analkyd-melamine varnish. In the case of the initial mass of thesurface-modified pigments, the surface coating was compensated by anadjustment to the initial mass. Percentages are by weight.

EXAMPLE 1

A suspension of 364 g of Pigment Violet 23 (C.I. No. 51319, used in theform of a presscake) and 2500 g of water is deagglomerated using astatic mixer (Laborpilot 2000, IKA, Staufen, Germany) at 6000 min−1 for1 hour. Added to the suspension is a solution of 156 g of modifiedacrylate copolymer (10% vinylimidazole, 90% butyl methacrylate, aminenumber: 30 mg KOH/g, M_(n)=13 500 g/mol, M_(w)=31 000 g/mol), 144 g ofmethoxypropyl acetate and 2310 ml of isobutanol. The reaction mixture isdeagglomerated with the static mixer for a further 60 minutes. Followinga steam distillation the surface-modified Pigment Violet 23 is isolatedby filtration and dried in a drying oven at 60° C. After final drygrinding (in a number of portions, using an IKA M 20 mill), 452 g ofeasily dispersible pigment violet are obtained.

EXAMPLE 2

293.4 g of Pigment Violet 23 (C. I. No. 51319, used in presscake form)are admixed with 2.4 l of water and coarsely homogenized. Thereafter thesuspension is ground

in a DCP Superflow 12 mill (from Drais) for 30 minutes, with an averageresidence time of 4 minutes. After the end of grinding, 400 g of theabove suspension (solids content: 9.68%) are introduced into a 2 l flaskwith KPG stirrer and, with stirring, are admixed with a solution of 16.6g of acrylate copolymer (10% vinylimidazole, 90% butyl methacrylate,amine number: 30 mg KOH/g, M_(n)=13 500 g/mol, M_(w)=31 000 g/mol), 14.4g of methoxypropyl acetate, 1.0 g of n-butyl acetate and 295 ml ofisobutanol, the reaction mixture being stirred at 40° C. for 90 minutes.This is followed by a steam distillation, in the course of which 360 mlof organic phase are separated off. During the steam distillation, smallbeads of pigment, 1-2 mm in size, are formed. These beads are filteredoff, washed with water and dried in a drying oven at 60° C. After finaldry grinding (in a number of portions, using an IKA M 20 mill), aneasily dispersible violet pigment is obtained.

EXAMPLE 3

100 g of Pigment Orange 36 (C.I. No. 11780, used in presscake form) areadmixed with 100 ml of isobutanol in a dissolver with toothed disk andthe mixture is dispersed at 1500 rpm for 10 min. Thereafter a solutionof 11.2 g of acrylate copolymer (10% vinylimidazole, 90% butylmethacrylate) in methoxypropyl acetate and isobutanol is added and themixture is stirred at 1500 rpm for a further hour. This is followed bysteam distillation to remove the organic solvent. After finalfiltration, drying at 60° C. and dry grinding (in a number of portions,using an IKA M 20 mill), an easily dispersible orange pigment isobtained.

The pigments produced in Examples 1 to 3 are tested in an alkyd-melaminebaking varnish. The varnish system is composed of a grinding varnish, aletdown mixture, and a white paint:

Grinding Varnish:

35% and 50% polyester resin solution in Solvesso 100

Letdown Mixture:

26.4 g polyester resin solution, 29.4 g alkyd resin solution, 35.8 gmelamine resin solution, 6.2 g high-boilers mixture, 2.2 g Solvesso 100

White Paint (30%):

Standard white paint based on Kronos TiO₂, polyester resin solution,alkyd resin solution, additives, Solvesso 100

EXAMPLE I: COMPARATIVE EXAMPLE

The masstone paint was produced by dispersing 21.0 g of alkyd melaminegrinding varnish and 9.0 g of Pigment Orange 36 (C.I. No. 11780)together with 85 g of glass beads (3 mm) in a Scandex mixer (BA-S 20,Scandex, Bromma, Sweden) for 30 minutes. Subsequently, with slowstirring using a glass rod, 60 g of letdown mixture are added, followedby dispersion again in the Scandex mixer for 3 minutes. Subsequently theglass beads are removed by filtration.

To produce the white reduction, 6.0 g of the above masstone paint arehomogenized with 20 g of alkyd melamine white paint (30%) by means ofsimple stirred incorporation.

EXAMPLE II

In a dissolver with toothed disk (VMA-Getzmann GmbH, Reichshof, Germany)40 g of alkyd-melamine grinding varnish are dispersed with 20 g of theeasily dispersible pigment from Example 3 at 3800 rpm and 50° C. for 30minutes. 10 g of this pigmented grinding varnish are then admixedgradually, with slow stirring using a glass rod, with 20 g of letdownmixture at room temperature.

To produce the white reduction, 6.0 g of the above masstone paint arehomogenized with 20 g of alkyd-melamine white paint (30% TiO₂) by meansof simple stirred incorporation.

EXAMPLE III, COMPARATIVE EXAMPLE

To produce the masstone paint, 26.4 g of alkyd-melamine grinding varnishand 3.6 g of C.I. Pigment Violet 23 (C.I. No. 51319, Hostaperm Violet RLspec.) are dispersed together with 85 g of glass beads (3 mm) in theScandex mixer for 30 minutes. Thereafter, with slow stirring using aglass rod, 60 g of letdown mixture are added, followed by reneweddispersion in the Scandex for 3 minutes. Subsequently the glass beadsare removed by filtration.

For the white reduction, 7.5 g of the above masstone paint arehomogenized with 20 g of alkyd melamine white paint (30% TiO₂) by meansof simple stirred incorporation.

EXAMPLE IV

In a dissolver, 49.7 g of alkyd-melamine grinding varnish are dispersedwith 10.3 g of easily dispersible violet pigment (Example 1) at 50° C.and 3800 rpm for 30 minutes. 10 g of this pigmented grinding varnish arethen admixed gradually, with slow stirring using a glass rod, with 20 gof letdown mixture at room temperature.

For the white reduction, 7.5 g of the above masstone paint arehomogenised with 20 g of alkyd-melamine white paint (30% TiO₂) by meansof simple stirred incorporation.

The easily dispersible pigments exhibit a significantly higher colorintensity in the alkyd-melamine varnish in comparison to theconventional pigments. The table shows the resultant color intensity ofthe respective pigment in an alkyd-melamine varnish followingappropriate white reduction. Type of dispersing in grinding Examplevarnish Color intensity III Scandex mixer 100% IV Dissolver 122%

EXAMPLE V

The color intensity determined as a function of dispersing time showsthat the easily dispersible, surface-coated pigments develop a highercolor intensity in an alkyd-melamine varnish, when dispersed in aScandex mixer (Scandex, Bromma, Sweden) for the same dispersing time andtype, than the Hostaperm Violet RL spec. (Clariant) reference pigment.The difference in pure-pigment concentration was taken into account inthis series of experiments and was compensated by means of a higherpigment concentration in the case of the surface-coated, easilydispersible pigments.

Procedure:

26.4 g of alkyd-melamine grinding varnish and 3.6 g of Hostaperm VioletRL spec. are each dispersed together with 85 g of glass beads (3 mm) inthe Scandex mixer for 15, 30 and 60 minutes, respectively. Thereafter,with slow stirring using a glass rod, 60 g of letdown mixture are addedand dispersion is repeated in the Scandex mixer for 3 minutes.Subsequently the glass beads are removed by filtration. To produce thewhite reduction varnish, 7.5 g of the above masstone varnish are admixedwith 20 g of an alkyd-melamine reduction varnish (30% TiO₂) and themixture is homogenized.

With the surface-coated pigment (Example 1) a similar procedure iscarried out, but using 5.1 g of pigment (corresponding to 3.6 g of purepigment) and 24.9 g of grinding varnish. Color Color intensity Colorintensity intensity Pigment after 15 min after 30 min after 60 minHostaperm Violet 87 97 100 RL spec. (Clariant) Example 1 100 100 100

1) A method of pigmenting a solventborne, nonaqueous organic coatingmaterial comprising the steps of incorporating a finely divided organicpigment coated with at least one amino-containing (meth)acrylatecopolymer into a solventborne organic coating material with an energyinput reduced by at least 20% as compared with the correspondinguncoated pigment. 2) The method of claim 1, wherein the organic coatingmaterial is a solventborne baking varnish or a solventbornetwo-component varnish. 3) The method of claim 1, wherein the organiccoating material is an alkyd-melamine resin varnish, acrylic-melamineresin varnish, polyester varnish or high-solids acrylic resin varnish.4) The method of claim 1, wherein the organic coating material is aprinting ink or ink-jet ink. 5) The method of claim 1, wherein theorganic pigment is a pigment selected from the group consisting of azopigments, Naphtol, benzimidazolone, metal complex pigments, andpolycyclic pigments. 6) The method of claim 1, wherein the at least oneamino containing (meth)acrylate copolymer has a molar mass of between2000 and 100 000 g/mol. 7) The method of claim 1, wherein the at leastone amino-containing (meth)acrylate copolymer has an amine number ofbetween 20 and 70 mg KOH/g. 8) The method of claim 1, wherein the finelydivided organic pigment coated with at least one amino-containing(meth)acrylate copolymer is obtained by mixing an aqueous, finishedpresscake of the organic pigment with water, deagglomerating the waterand presscake in a static mixer in the presence of the at least oneamino-containing (meth)acrylate copolymer to form a deagglomeratedmixture, subjecting the deagglomerated mixture to steam distillation toform a solid, isolating the solid by filtration, and drying the solid toform a coated pigment. 9) The method of claim 8, wherein thedeagglomerating step deagglomerates the organic pigment to a particlesize distribution of 0.1 to 10 μm. 10) The method of one claim 1,wherein the at least one amino-containing (meth)acrylate copolymer isapplied to the organic pigment in an amount of 5% to 50% by weight,based on the total weight of the coated pigment. 11) The method of claim1, wherein the organic pigment is selected from the group consisting ofmonoazo, diazo, isoindolinone, isoindoline, anthanthrone, thioindigo,thiazineindigo, triarylcarbonium, quinophthalone, anthraquinone,dioxazine, phthalocyanine, quinacridone, quinacridonequinone,indanthrone, perylene, perinone, pyranthrone, diketopyrrolopyrrole,isoviolanthrone and azomethine pigments. 12) A pigmented solventbornenonaqueous organic coating material made in accordance with the methodof claim
 1. 13) The pigmented solventborne nonaqueous organic coatingmaterial of claim 12, wherein the organic coating material is a bakingvarnish, two component varnish, a printing ink or ink jet ink.